I want to replace the slightly battered and corroded coil on my Starfire it's the original Lucas coil made October 68. Can I fit any coil that will fit in the bracket (48mmx130mm) or do I need a specific coil that will suit the electronic sparks.
I'm not sure there is a wide choice available but the only requirement, I believe, is that it is a 12 V coil.
Going through this right now on my 67 B25.
Mine came with a 6V coil on it and it ran with the Boyer Brandsen EI just fine, till the other day. I had to push it home for the first time. No spark. I was hoping my EI didn't take a dump. Battery has 12.6 and is charging so the alternator is good.
I read online doing research that Boyer states primary resistance under 3.2 will overheat the box. Mine measured in at 2.6. Boyer box overheating?
I bought a 12V coil for it from Ebay (vintage triumph supply) here:
https://www.ebay.com/itm/254767558881
Going to install it and see what happens. All the connections are good and I find no shorts in the harness. Fingers crossed.
This coil is the correct physical size to fit in my coil mount. They say not to over-tighten the mount. If you squeeze the coil, it will short out????
I have noticed some coils say they're ballast or non ballast any idea which type works better with Boyer ignition.
Quote from: AltcarBob on 22 Jun, 2023, 21:24
I have noticed some coils say they're ballast or non ballast any idea which type works better with Boyer ignition.
No idea about the ballast or not. I know some cars came with ballast resistors that would bolt close to the coil.
That said, the linked coil worked and fit just fine. Had to swap over a third spade connector from the old coil. No biggy.
The primary resistance measured at 4.8 ohms, far above the one I took out. The old one bench measured at 2.4 ohms once it was unhooked and out of the bike. Just put a few miles on her and she's never run better. Really happy I didn't cook my Boyer unit.
I think I will have to ask Boyer Bransden for some advice. I am way out of my depth with elastictrickery, give me a mechanical problem and I can usually fix it but my brain shuts down when electrons come into it
I would check the recommended by Boyer.
Some new coils are smaller than the originals. Just wrapped part of an inner tube around mine so the clamp was a snug fit.
I think my C15 has got an old 12v car one on it, so has my Meteor Minor. They both work fine but are not on electronic ignition.
I wouldn't think it a problem though as the boyer is only a glorified switch anyway, just like the pazon one
As said, the B-B EI system is designed to work ideally with a 12 V coil or 2 x 6 V coils in series - it needs to see a total of at least 3.5 Ohm.
Some older cars used ballast resistors but these were used with a 9 V coil. As long as it is a 12 V coil, it doesn't matter whether it was designed specifically for a motorbike or a car.
I have bought an Indian Lucas coil meant for a Royal Oilfield 350. Only £17.99 so if it's not suitable it's not too big a hit.